xref: /linux/drivers/misc/ad525x_dpot.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * ad525x_dpot: Driver for the Analog Devices digital potentiometers
3  * Copyright (c) 2009-2010 Analog Devices, Inc.
4  * Author: Michael Hennerich <hennerich@blackfin.uclinux.org>
5  *
6  * DEVID		#Wipers		#Positions 	Resistor Options (kOhm)
7  * AD5258		1		64		1, 10, 50, 100
8  * AD5259		1		256		5, 10, 50, 100
9  * AD5251		2		64		1, 10, 50, 100
10  * AD5252		2		256		1, 10, 50, 100
11  * AD5255		3		512		25, 250
12  * AD5253		4		64		1, 10, 50, 100
13  * AD5254		4		256		1, 10, 50, 100
14  * AD5160		1		256		5, 10, 50, 100
15  * AD5161		1		256		5, 10, 50, 100
16  * AD5162		2		256		2.5, 10, 50, 100
17  * AD5165		1		256		100
18  * AD5200		1		256		10, 50
19  * AD5201		1		33		10, 50
20  * AD5203		4		64		10, 100
21  * AD5204		4		256		10, 50, 100
22  * AD5206		6		256		10, 50, 100
23  * AD5207		2		256		10, 50, 100
24  * AD5231		1		1024		10, 50, 100
25  * AD5232		2		256		10, 50, 100
26  * AD5233		4		64		10, 50, 100
27  * AD5235		2		1024		25, 250
28  * AD5260		1		256		20, 50, 200
29  * AD5262		2		256		20, 50, 200
30  * AD5263		4		256		20, 50, 200
31  * AD5290		1		256		10, 50, 100
32  * AD5291		1		256		20, 50, 100  (20-TP)
33  * AD5292		1		1024		20, 50, 100  (20-TP)
34  * AD5293		1		1024		20, 50, 100
35  * AD7376		1		128		10, 50, 100, 1M
36  * AD8400		1		256		1, 10, 50, 100
37  * AD8402		2		256		1, 10, 50, 100
38  * AD8403		4		256		1, 10, 50, 100
39  * ADN2850		3		512		25, 250
40  * AD5241		1		256		10, 100, 1M
41  * AD5246		1		128		5, 10, 50, 100
42  * AD5247		1		128		5, 10, 50, 100
43  * AD5245		1		256		5, 10, 50, 100
44  * AD5243		2		256		2.5, 10, 50, 100
45  * AD5248		2		256		2.5, 10, 50, 100
46  * AD5242		2		256		20, 50, 200
47  * AD5280		1		256		20, 50, 200
48  * AD5282		2		256		20, 50, 200
49  * ADN2860		3		512		25, 250
50  * AD5273		1		64		1, 10, 50, 100 (OTP)
51  * AD5171		1		64		5, 10, 50, 100 (OTP)
52  * AD5170		1		256		2.5, 10, 50, 100 (OTP)
53  * AD5172		2		256		2.5, 10, 50, 100 (OTP)
54  * AD5173		2		256		2.5, 10, 50, 100 (OTP)
55  * AD5270		1		1024		20, 50, 100 (50-TP)
56  * AD5271		1		256		20, 50, 100 (50-TP)
57  * AD5272		1		1024		20, 50, 100 (50-TP)
58  * AD5274		1		256		20, 50, 100 (50-TP)
59  *
60  * See Documentation/misc-devices/ad525x_dpot.txt for more info.
61  *
62  * derived from ad5258.c
63  * Copyright (c) 2009 Cyber Switching, Inc.
64  * Author: Chris Verges <chrisv@cyberswitching.com>
65  *
66  * derived from ad5252.c
67  * Copyright (c) 2006-2011 Michael Hennerich <hennerich@blackfin.uclinux.org>
68  *
69  * Licensed under the GPL-2 or later.
70  */
71 
72 #include <linux/module.h>
73 #include <linux/device.h>
74 #include <linux/kernel.h>
75 #include <linux/delay.h>
76 #include <linux/slab.h>
77 
78 #include "ad525x_dpot.h"
79 
80 /*
81  * Client data (each client gets its own)
82  */
83 
84 struct dpot_data {
85 	struct ad_dpot_bus_data	bdata;
86 	struct mutex update_lock;
87 	unsigned rdac_mask;
88 	unsigned max_pos;
89 	unsigned long devid;
90 	unsigned uid;
91 	unsigned feat;
92 	unsigned wipers;
93 	u16 rdac_cache[MAX_RDACS];
94 	DECLARE_BITMAP(otp_en_mask, MAX_RDACS);
95 };
96 
97 static inline int dpot_read_d8(struct dpot_data *dpot)
98 {
99 	return dpot->bdata.bops->read_d8(dpot->bdata.client);
100 }
101 
102 static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
103 {
104 	return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
105 }
106 
107 static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
108 {
109 	return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
110 }
111 
112 static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
113 {
114 	return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
115 }
116 
117 static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
118 {
119 	return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
120 }
121 
122 static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
123 {
124 	return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
125 }
126 
127 static s32 dpot_read_spi(struct dpot_data *dpot, u8 reg)
128 {
129 	unsigned ctrl = 0;
130 	int value;
131 
132 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
133 
134 		if (dpot->feat & F_RDACS_WONLY)
135 			return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
136 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
137 			dpot->uid == DPOT_UID(AD5292_ID) ||
138 			dpot->uid == DPOT_UID(AD5293_ID)) {
139 
140 			value = dpot_read_r8d8(dpot,
141 				DPOT_AD5291_READ_RDAC << 2);
142 
143 			if (dpot->uid == DPOT_UID(AD5291_ID))
144 				value = value >> 2;
145 
146 			return value;
147 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
148 			dpot->uid == DPOT_UID(AD5271_ID)) {
149 
150 			value = dpot_read_r8d8(dpot,
151 				DPOT_AD5270_1_2_4_READ_RDAC << 2);
152 
153 			if (value < 0)
154 				return value;
155 
156 			if (dpot->uid == DPOT_UID(AD5271_ID))
157 				value = value >> 2;
158 
159 			return value;
160 		}
161 
162 		ctrl = DPOT_SPI_READ_RDAC;
163 	} else if (reg & DPOT_ADDR_EEPROM) {
164 		ctrl = DPOT_SPI_READ_EEPROM;
165 	}
166 
167 	if (dpot->feat & F_SPI_16BIT)
168 		return dpot_read_r8d8(dpot, ctrl);
169 	else if (dpot->feat & F_SPI_24BIT)
170 		return dpot_read_r8d16(dpot, ctrl);
171 
172 	return -EFAULT;
173 }
174 
175 static s32 dpot_read_i2c(struct dpot_data *dpot, u8 reg)
176 {
177 	int value;
178 	unsigned ctrl = 0;
179 	switch (dpot->uid) {
180 	case DPOT_UID(AD5246_ID):
181 	case DPOT_UID(AD5247_ID):
182 		return dpot_read_d8(dpot);
183 	case DPOT_UID(AD5245_ID):
184 	case DPOT_UID(AD5241_ID):
185 	case DPOT_UID(AD5242_ID):
186 	case DPOT_UID(AD5243_ID):
187 	case DPOT_UID(AD5248_ID):
188 	case DPOT_UID(AD5280_ID):
189 	case DPOT_UID(AD5282_ID):
190 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
191 			0 : DPOT_AD5282_RDAC_AB;
192 		return dpot_read_r8d8(dpot, ctrl);
193 	case DPOT_UID(AD5170_ID):
194 	case DPOT_UID(AD5171_ID):
195 	case DPOT_UID(AD5273_ID):
196 			return dpot_read_d8(dpot);
197 	case DPOT_UID(AD5172_ID):
198 	case DPOT_UID(AD5173_ID):
199 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
200 			0 : DPOT_AD5172_3_A0;
201 		return dpot_read_r8d8(dpot, ctrl);
202 	case DPOT_UID(AD5272_ID):
203 	case DPOT_UID(AD5274_ID):
204 			dpot_write_r8d8(dpot,
205 				(DPOT_AD5270_1_2_4_READ_RDAC << 2), 0);
206 
207 			value = dpot_read_r8d16(dpot,
208 				DPOT_AD5270_1_2_4_RDAC << 2);
209 
210 			if (value < 0)
211 				return value;
212 			/*
213 			 * AD5272/AD5274 returns high byte first, however
214 			 * underling smbus expects low byte first.
215 			 */
216 			value = swab16(value);
217 
218 			if (dpot->uid == DPOT_UID(AD5271_ID))
219 				value = value >> 2;
220 		return value;
221 	default:
222 		if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
223 			return dpot_read_r8d16(dpot, (reg & 0xF8) |
224 					((reg & 0x7) << 1));
225 		else
226 			return dpot_read_r8d8(dpot, reg);
227 	}
228 }
229 
230 static s32 dpot_read(struct dpot_data *dpot, u8 reg)
231 {
232 	if (dpot->feat & F_SPI)
233 		return dpot_read_spi(dpot, reg);
234 	else
235 		return dpot_read_i2c(dpot, reg);
236 }
237 
238 static s32 dpot_write_spi(struct dpot_data *dpot, u8 reg, u16 value)
239 {
240 	unsigned val = 0;
241 
242 	if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD | DPOT_ADDR_OTP))) {
243 		if (dpot->feat & F_RDACS_WONLY)
244 			dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
245 
246 		if (dpot->feat & F_AD_APPDATA) {
247 			if (dpot->feat & F_SPI_8BIT) {
248 				val = ((reg & DPOT_RDAC_MASK) <<
249 					DPOT_MAX_POS(dpot->devid)) |
250 					value;
251 				return dpot_write_d8(dpot, val);
252 			} else if (dpot->feat & F_SPI_16BIT) {
253 				val = ((reg & DPOT_RDAC_MASK) <<
254 					DPOT_MAX_POS(dpot->devid)) |
255 					value;
256 				return dpot_write_r8d8(dpot, val >> 8,
257 					val & 0xFF);
258 			} else
259 				BUG();
260 		} else {
261 			if (dpot->uid == DPOT_UID(AD5291_ID) ||
262 				dpot->uid == DPOT_UID(AD5292_ID) ||
263 				dpot->uid == DPOT_UID(AD5293_ID)) {
264 
265 				dpot_write_r8d8(dpot, DPOT_AD5291_CTRLREG << 2,
266 						DPOT_AD5291_UNLOCK_CMD);
267 
268 				if (dpot->uid == DPOT_UID(AD5291_ID))
269 					value = value << 2;
270 
271 				return dpot_write_r8d8(dpot,
272 					(DPOT_AD5291_RDAC << 2) |
273 					(value >> 8), value & 0xFF);
274 			} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
275 				dpot->uid == DPOT_UID(AD5271_ID)) {
276 				dpot_write_r8d8(dpot,
277 						DPOT_AD5270_1_2_4_CTRLREG << 2,
278 						DPOT_AD5270_1_2_4_UNLOCK_CMD);
279 
280 				if (dpot->uid == DPOT_UID(AD5271_ID))
281 					value = value << 2;
282 
283 				return dpot_write_r8d8(dpot,
284 					(DPOT_AD5270_1_2_4_RDAC << 2) |
285 					(value >> 8), value & 0xFF);
286 			}
287 			val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
288 		}
289 	} else if (reg & DPOT_ADDR_EEPROM) {
290 		val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
291 	} else if (reg & DPOT_ADDR_CMD) {
292 		switch (reg) {
293 		case DPOT_DEC_ALL_6DB:
294 			val = DPOT_SPI_DEC_ALL_6DB;
295 			break;
296 		case DPOT_INC_ALL_6DB:
297 			val = DPOT_SPI_INC_ALL_6DB;
298 			break;
299 		case DPOT_DEC_ALL:
300 			val = DPOT_SPI_DEC_ALL;
301 			break;
302 		case DPOT_INC_ALL:
303 			val = DPOT_SPI_INC_ALL;
304 			break;
305 		}
306 	} else if (reg & DPOT_ADDR_OTP) {
307 		if (dpot->uid == DPOT_UID(AD5291_ID) ||
308 			dpot->uid == DPOT_UID(AD5292_ID)) {
309 			return dpot_write_r8d8(dpot,
310 				DPOT_AD5291_STORE_XTPM << 2, 0);
311 		} else if (dpot->uid == DPOT_UID(AD5270_ID) ||
312 			dpot->uid == DPOT_UID(AD5271_ID)) {
313 			return dpot_write_r8d8(dpot,
314 				DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
315 		}
316 	} else
317 		BUG();
318 
319 	if (dpot->feat & F_SPI_16BIT)
320 		return dpot_write_r8d8(dpot, val, value);
321 	else if (dpot->feat & F_SPI_24BIT)
322 		return dpot_write_r8d16(dpot, val, value);
323 
324 	return -EFAULT;
325 }
326 
327 static s32 dpot_write_i2c(struct dpot_data *dpot, u8 reg, u16 value)
328 {
329 	/* Only write the instruction byte for certain commands */
330 	unsigned tmp = 0, ctrl = 0;
331 
332 	switch (dpot->uid) {
333 	case DPOT_UID(AD5246_ID):
334 	case DPOT_UID(AD5247_ID):
335 		return dpot_write_d8(dpot, value);
336 		break;
337 
338 	case DPOT_UID(AD5245_ID):
339 	case DPOT_UID(AD5241_ID):
340 	case DPOT_UID(AD5242_ID):
341 	case DPOT_UID(AD5243_ID):
342 	case DPOT_UID(AD5248_ID):
343 	case DPOT_UID(AD5280_ID):
344 	case DPOT_UID(AD5282_ID):
345 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
346 			0 : DPOT_AD5282_RDAC_AB;
347 		return dpot_write_r8d8(dpot, ctrl, value);
348 		break;
349 	case DPOT_UID(AD5171_ID):
350 	case DPOT_UID(AD5273_ID):
351 		if (reg & DPOT_ADDR_OTP) {
352 			tmp = dpot_read_d8(dpot);
353 			if (tmp >> 6) /* Ready to Program? */
354 				return -EFAULT;
355 			ctrl = DPOT_AD5273_FUSE;
356 		}
357 		return dpot_write_r8d8(dpot, ctrl, value);
358 		break;
359 	case DPOT_UID(AD5172_ID):
360 	case DPOT_UID(AD5173_ID):
361 		ctrl = ((reg & DPOT_RDAC_MASK) == DPOT_RDAC0) ?
362 			0 : DPOT_AD5172_3_A0;
363 		if (reg & DPOT_ADDR_OTP) {
364 			tmp = dpot_read_r8d16(dpot, ctrl);
365 			if (tmp >> 14) /* Ready to Program? */
366 				return -EFAULT;
367 			ctrl |= DPOT_AD5170_2_3_FUSE;
368 		}
369 		return dpot_write_r8d8(dpot, ctrl, value);
370 		break;
371 	case DPOT_UID(AD5170_ID):
372 		if (reg & DPOT_ADDR_OTP) {
373 			tmp = dpot_read_r8d16(dpot, tmp);
374 			if (tmp >> 14) /* Ready to Program? */
375 				return -EFAULT;
376 			ctrl = DPOT_AD5170_2_3_FUSE;
377 		}
378 		return dpot_write_r8d8(dpot, ctrl, value);
379 		break;
380 	case DPOT_UID(AD5272_ID):
381 	case DPOT_UID(AD5274_ID):
382 		dpot_write_r8d8(dpot, DPOT_AD5270_1_2_4_CTRLREG << 2,
383 				DPOT_AD5270_1_2_4_UNLOCK_CMD);
384 
385 		if (reg & DPOT_ADDR_OTP)
386 			return dpot_write_r8d8(dpot,
387 					DPOT_AD5270_1_2_4_STORE_XTPM << 2, 0);
388 
389 		if (dpot->uid == DPOT_UID(AD5274_ID))
390 			value = value << 2;
391 
392 		return dpot_write_r8d8(dpot, (DPOT_AD5270_1_2_4_RDAC << 2) |
393 				       (value >> 8), value & 0xFF);
394 		break;
395 	default:
396 		if (reg & DPOT_ADDR_CMD)
397 			return dpot_write_d8(dpot, reg);
398 
399 		if (dpot->max_pos > 256)
400 			return dpot_write_r8d16(dpot, (reg & 0xF8) |
401 						((reg & 0x7) << 1), value);
402 		else
403 			/* All other registers require instruction + data bytes */
404 			return dpot_write_r8d8(dpot, reg, value);
405 	}
406 }
407 
408 static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
409 {
410 	if (dpot->feat & F_SPI)
411 		return dpot_write_spi(dpot, reg, value);
412 	else
413 		return dpot_write_i2c(dpot, reg, value);
414 }
415 
416 /* sysfs functions */
417 
418 static ssize_t sysfs_show_reg(struct device *dev,
419 			      struct device_attribute *attr,
420 			      char *buf, u32 reg)
421 {
422 	struct dpot_data *data = dev_get_drvdata(dev);
423 	s32 value;
424 
425 	if (reg & DPOT_ADDR_OTP_EN)
426 		return sprintf(buf, "%s\n",
427 			test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask) ?
428 			"enabled" : "disabled");
429 
430 
431 	mutex_lock(&data->update_lock);
432 	value = dpot_read(data, reg);
433 	mutex_unlock(&data->update_lock);
434 
435 	if (value < 0)
436 		return -EINVAL;
437 	/*
438 	 * Let someone else deal with converting this ...
439 	 * the tolerance is a two-byte value where the MSB
440 	 * is a sign + integer value, and the LSB is a
441 	 * decimal value.  See page 18 of the AD5258
442 	 * datasheet (Rev. A) for more details.
443 	 */
444 
445 	if (reg & DPOT_REG_TOL)
446 		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
447 	else
448 		return sprintf(buf, "%u\n", value & data->rdac_mask);
449 }
450 
451 static ssize_t sysfs_set_reg(struct device *dev,
452 			     struct device_attribute *attr,
453 			     const char *buf, size_t count, u32 reg)
454 {
455 	struct dpot_data *data = dev_get_drvdata(dev);
456 	unsigned long value;
457 	int err;
458 
459 	if (reg & DPOT_ADDR_OTP_EN) {
460 		if (!strncmp(buf, "enabled", sizeof("enabled")))
461 			set_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
462 		else
463 			clear_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask);
464 
465 		return count;
466 	}
467 
468 	if ((reg & DPOT_ADDR_OTP) &&
469 		!test_bit(DPOT_RDAC_MASK & reg, data->otp_en_mask))
470 		return -EPERM;
471 
472 	err = kstrtoul(buf, 10, &value);
473 	if (err)
474 		return err;
475 
476 	if (value > data->rdac_mask)
477 		value = data->rdac_mask;
478 
479 	mutex_lock(&data->update_lock);
480 	dpot_write(data, reg, value);
481 	if (reg & DPOT_ADDR_EEPROM)
482 		msleep(26);	/* Sleep while the EEPROM updates */
483 	else if (reg & DPOT_ADDR_OTP)
484 		msleep(400);	/* Sleep while the OTP updates */
485 	mutex_unlock(&data->update_lock);
486 
487 	return count;
488 }
489 
490 static ssize_t sysfs_do_cmd(struct device *dev,
491 			    struct device_attribute *attr,
492 			    const char *buf, size_t count, u32 reg)
493 {
494 	struct dpot_data *data = dev_get_drvdata(dev);
495 
496 	mutex_lock(&data->update_lock);
497 	dpot_write(data, reg, 0);
498 	mutex_unlock(&data->update_lock);
499 
500 	return count;
501 }
502 
503 /* ------------------------------------------------------------------------- */
504 
505 #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
506 show_##_name(struct device *dev, \
507 			  struct device_attribute *attr, char *buf) \
508 { \
509 	return sysfs_show_reg(dev, attr, buf, _reg); \
510 }
511 
512 #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
513 set_##_name(struct device *dev, \
514 			 struct device_attribute *attr, \
515 			 const char *buf, size_t count) \
516 { \
517 	return sysfs_set_reg(dev, attr, buf, count, _reg); \
518 }
519 
520 #define DPOT_DEVICE_SHOW_SET(name, reg) \
521 DPOT_DEVICE_SHOW(name, reg) \
522 DPOT_DEVICE_SET(name, reg) \
523 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
524 
525 #define DPOT_DEVICE_SHOW_ONLY(name, reg) \
526 DPOT_DEVICE_SHOW(name, reg) \
527 static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
528 
529 DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
530 DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
531 DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
532 DPOT_DEVICE_SHOW_SET(otp0, DPOT_ADDR_OTP | DPOT_RDAC0);
533 DPOT_DEVICE_SHOW_SET(otp0en, DPOT_ADDR_OTP_EN | DPOT_RDAC0);
534 
535 DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
536 DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
537 DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
538 DPOT_DEVICE_SHOW_SET(otp1, DPOT_ADDR_OTP | DPOT_RDAC1);
539 DPOT_DEVICE_SHOW_SET(otp1en, DPOT_ADDR_OTP_EN | DPOT_RDAC1);
540 
541 DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
542 DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
543 DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
544 DPOT_DEVICE_SHOW_SET(otp2, DPOT_ADDR_OTP | DPOT_RDAC2);
545 DPOT_DEVICE_SHOW_SET(otp2en, DPOT_ADDR_OTP_EN | DPOT_RDAC2);
546 
547 DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
548 DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
549 DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
550 DPOT_DEVICE_SHOW_SET(otp3, DPOT_ADDR_OTP | DPOT_RDAC3);
551 DPOT_DEVICE_SHOW_SET(otp3en, DPOT_ADDR_OTP_EN | DPOT_RDAC3);
552 
553 DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
554 DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
555 DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
556 DPOT_DEVICE_SHOW_SET(otp4, DPOT_ADDR_OTP | DPOT_RDAC4);
557 DPOT_DEVICE_SHOW_SET(otp4en, DPOT_ADDR_OTP_EN | DPOT_RDAC4);
558 
559 DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
560 DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
561 DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
562 DPOT_DEVICE_SHOW_SET(otp5, DPOT_ADDR_OTP | DPOT_RDAC5);
563 DPOT_DEVICE_SHOW_SET(otp5en, DPOT_ADDR_OTP_EN | DPOT_RDAC5);
564 
565 static const struct attribute *dpot_attrib_wipers[] = {
566 	&dev_attr_rdac0.attr,
567 	&dev_attr_rdac1.attr,
568 	&dev_attr_rdac2.attr,
569 	&dev_attr_rdac3.attr,
570 	&dev_attr_rdac4.attr,
571 	&dev_attr_rdac5.attr,
572 	NULL
573 };
574 
575 static const struct attribute *dpot_attrib_eeprom[] = {
576 	&dev_attr_eeprom0.attr,
577 	&dev_attr_eeprom1.attr,
578 	&dev_attr_eeprom2.attr,
579 	&dev_attr_eeprom3.attr,
580 	&dev_attr_eeprom4.attr,
581 	&dev_attr_eeprom5.attr,
582 	NULL
583 };
584 
585 static const struct attribute *dpot_attrib_otp[] = {
586 	&dev_attr_otp0.attr,
587 	&dev_attr_otp1.attr,
588 	&dev_attr_otp2.attr,
589 	&dev_attr_otp3.attr,
590 	&dev_attr_otp4.attr,
591 	&dev_attr_otp5.attr,
592 	NULL
593 };
594 
595 static const struct attribute *dpot_attrib_otp_en[] = {
596 	&dev_attr_otp0en.attr,
597 	&dev_attr_otp1en.attr,
598 	&dev_attr_otp2en.attr,
599 	&dev_attr_otp3en.attr,
600 	&dev_attr_otp4en.attr,
601 	&dev_attr_otp5en.attr,
602 	NULL
603 };
604 
605 static const struct attribute *dpot_attrib_tolerance[] = {
606 	&dev_attr_tolerance0.attr,
607 	&dev_attr_tolerance1.attr,
608 	&dev_attr_tolerance2.attr,
609 	&dev_attr_tolerance3.attr,
610 	&dev_attr_tolerance4.attr,
611 	&dev_attr_tolerance5.attr,
612 	NULL
613 };
614 
615 /* ------------------------------------------------------------------------- */
616 
617 #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
618 set_##_name(struct device *dev, \
619 			 struct device_attribute *attr, \
620 			 const char *buf, size_t count) \
621 { \
622 	return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
623 } \
624 static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
625 
626 DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
627 DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
628 DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
629 DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
630 
631 static struct attribute *ad525x_attributes_commands[] = {
632 	&dev_attr_inc_all.attr,
633 	&dev_attr_dec_all.attr,
634 	&dev_attr_inc_all_6db.attr,
635 	&dev_attr_dec_all_6db.attr,
636 	NULL
637 };
638 
639 static const struct attribute_group ad525x_group_commands = {
640 	.attrs = ad525x_attributes_commands,
641 };
642 
643 static int ad_dpot_add_files(struct device *dev,
644 		unsigned features, unsigned rdac)
645 {
646 	int err = sysfs_create_file(&dev->kobj,
647 		dpot_attrib_wipers[rdac]);
648 	if (features & F_CMD_EEP)
649 		err |= sysfs_create_file(&dev->kobj,
650 			dpot_attrib_eeprom[rdac]);
651 	if (features & F_CMD_TOL)
652 		err |= sysfs_create_file(&dev->kobj,
653 			dpot_attrib_tolerance[rdac]);
654 	if (features & F_CMD_OTP) {
655 		err |= sysfs_create_file(&dev->kobj,
656 			dpot_attrib_otp_en[rdac]);
657 		err |= sysfs_create_file(&dev->kobj,
658 			dpot_attrib_otp[rdac]);
659 	}
660 
661 	if (err)
662 		dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
663 			rdac);
664 
665 	return err;
666 }
667 
668 static inline void ad_dpot_remove_files(struct device *dev,
669 		unsigned features, unsigned rdac)
670 {
671 	sysfs_remove_file(&dev->kobj,
672 		dpot_attrib_wipers[rdac]);
673 	if (features & F_CMD_EEP)
674 		sysfs_remove_file(&dev->kobj,
675 			dpot_attrib_eeprom[rdac]);
676 	if (features & F_CMD_TOL)
677 		sysfs_remove_file(&dev->kobj,
678 			dpot_attrib_tolerance[rdac]);
679 	if (features & F_CMD_OTP) {
680 		sysfs_remove_file(&dev->kobj,
681 			dpot_attrib_otp_en[rdac]);
682 		sysfs_remove_file(&dev->kobj,
683 			dpot_attrib_otp[rdac]);
684 	}
685 }
686 
687 int ad_dpot_probe(struct device *dev,
688 		struct ad_dpot_bus_data *bdata, unsigned long devid,
689 			    const char *name)
690 {
691 
692 	struct dpot_data *data;
693 	int i, err = 0;
694 
695 	data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
696 	if (!data) {
697 		err = -ENOMEM;
698 		goto exit;
699 	}
700 
701 	dev_set_drvdata(dev, data);
702 	mutex_init(&data->update_lock);
703 
704 	data->bdata = *bdata;
705 	data->devid = devid;
706 
707 	data->max_pos = 1 << DPOT_MAX_POS(devid);
708 	data->rdac_mask = data->max_pos - 1;
709 	data->feat = DPOT_FEAT(devid);
710 	data->uid = DPOT_UID(devid);
711 	data->wipers = DPOT_WIPERS(devid);
712 
713 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
714 		if (data->wipers & (1 << i)) {
715 			err = ad_dpot_add_files(dev, data->feat, i);
716 			if (err)
717 				goto exit_remove_files;
718 			/* power-up midscale */
719 			if (data->feat & F_RDACS_WONLY)
720 				data->rdac_cache[i] = data->max_pos / 2;
721 		}
722 
723 	if (data->feat & F_CMD_INC)
724 		err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
725 
726 	if (err) {
727 		dev_err(dev, "failed to register sysfs hooks\n");
728 		goto exit_free;
729 	}
730 
731 	dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
732 		 name, data->max_pos);
733 
734 	return 0;
735 
736 exit_remove_files:
737 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
738 		if (data->wipers & (1 << i))
739 			ad_dpot_remove_files(dev, data->feat, i);
740 
741 exit_free:
742 	kfree(data);
743 	dev_set_drvdata(dev, NULL);
744 exit:
745 	dev_err(dev, "failed to create client for %s ID 0x%lX\n",
746 		name, devid);
747 	return err;
748 }
749 EXPORT_SYMBOL(ad_dpot_probe);
750 
751 int ad_dpot_remove(struct device *dev)
752 {
753 	struct dpot_data *data = dev_get_drvdata(dev);
754 	int i;
755 
756 	for (i = DPOT_RDAC0; i < MAX_RDACS; i++)
757 		if (data->wipers & (1 << i))
758 			ad_dpot_remove_files(dev, data->feat, i);
759 
760 	kfree(data);
761 
762 	return 0;
763 }
764 EXPORT_SYMBOL(ad_dpot_remove);
765 
766 
767 MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
768 	      "Michael Hennerich <hennerich@blackfin.uclinux.org>");
769 MODULE_DESCRIPTION("Digital potentiometer driver");
770 MODULE_LICENSE("GPL");
771